1. Field of the Invention
The present invention generally relates to a well pumping unit utilizing a walking beam that is longitudinally adjustable in length in order to vary the ratio of the length between the fulcrum point of the beam and the end of the beam connected with a pump rod as compared to the length of the beam between the pivot point and the point at which force is applied to the beam to oscillate it about the pivot point. By telescopically adjusting the walking beam and at the same time moving the power unit connected with the walking beam, the beam can be balanced to enable minimum energy to be applied to the beam to operate a downhole pump. The length of the connecting rod which connects a rotating eccentric powered by a power unit to the walking beam is adjustable in length to compensate for variations in movement of the pump rod resulting from longitudinal adjustment of the beam. The use of the unique features of this invention enables the horsepower requirements of a pump jack to be materially reduced with this invention requiring a smaller electric motor or other power unit such as a one horsepower unit as compared to a 3 to 5 horsepower unit normally employed on a pump jack.
2. Description of the Prior Art
My prior U.S. Pat. No. 4,586,879 issued May 6, 1986 discloses a well pumping unit associated with a downhole pump which includes a cable structure and pulley arrangements to enable the use of a smaller power unit to operate the downhole pump. This prior patent and the other prior patents of record in that patent are incorporated herein by reference thereto. None of the prior art discloses a telescopically adjustable walking beam incorporated into a pump jack together with a movable power unit connected to the adjustable component of the walking beam through a power transfer rod of adjustable length to enable the beam to be substantially balanced with the power unit being adjustable and the connection between the power unit and the adjustable beam being adjustable as incorporated into the present invention.